updt exclusions, change contributing link

.github/workflows/lychee_links.yaml

@@ -38,11 +38,12 @@ jobs:
             --accept 200,429
             --exclude "https://tiles.stadiamaps.com/*|https://b.tile.openstreetmap.org/*"
             --exclude "https://cartodb-basemaps-c.global.ssl.fastly.net/*"
-            --exclude "https://events.mapbox.com/*|https://api.mapbox.cn/*"
+            --exclude "https://events.mapbox.com/*|https://events.mapbox.cn/*|https://api.mapbox.cn/*"
             --exclude "https://github.com/mikolalysenko/glsl-read-float/*"
             --exclude "https://fonts.openmaptiles.org/*"
             --exclude "https://a.tile.openstreetmap.org/*"
             --exclude "https://cdn.plot.ly/*"
+            --exclude "https://doi.org/*"
             --exclude-path ./CHANGELOG.md
             --exclude-path asv.conf.json
             --exclude-path docs/conf.py

CONTRIBUTING.md

@@ -62,7 +62,7 @@ You now have everything you need to start making changes!
 
 ### B. Writing your code
 
-6. PyBOP is developed in [Python](https://en.wikipedia.org/wiki/Python_(programming_language)), and makes heavy use of [NumPy](https://en.wikipedia.org/wiki/NumPy) (see also [NumPy for MatLab users](https://numpy.org/doc/stable/user/numpy-for-matlab-users.html) and [Python for R users](https://www.hackerearth.com/blog/developers/how-can-r-users-start-learning-python-for-data-science/)).
+6. PyBOP is developed in [Python](https://en.wikipedia.org/wiki/Python_(programming_language)), and makes heavy use of [NumPy](https://en.wikipedia.org/wiki/NumPy) (see also [NumPy for MatLab users](https://numpy.org/doc/stable/user/numpy-for-matlab-users.html) and [Python for R users](https://rebeccabarter.com/blog/2023-09-11-from_r_to_python)).
 7. Make sure to follow our [coding style guidelines](#coding-style-guidelines).
 8. Commit your changes to your branch with [useful, descriptive commit messages](https://chris.beams.io/posts/git-commit/): Remember these are publicly visible and should still make sense a few months ahead in time. While developing, you can keep using the GitHub issue you're working on as a place for discussion. [Refer to your commits](https://stackoverflow.com/questions/8910271/how-can-i-reference-a-commit-in-an-issue-comment-on-github) when discussing specific lines of code.
 9. If you want to add a dependency on another library, or re-use code you found somewhere else, have a look at [these guidelines](#dependencies-and-reusing-code).